H - Y (Hydrogen - Yttrium)

Condensed Phases

Yttrium forms two hydrides with large homogeneity fields. Yttrium dihydride (nominal composition - YH₂) has a fcc lattice (type (CaF₂) with lattice parameters between 0.5199 and 0.5209 nm (depending on hydrogen concentration) [62Flo, 62Peb, 65Yan]. Yttrium trihydride (nominal composition - YH₃) has a hexagonal lattice with lattice parameters a = 0.3659 to 0.3674 nm, and c = 0.6586 to 0.6659 nm [62Flo, 62Lun, 62Peb]. At room temperature, the homogeneity fields have the following composition limits: yttrium solid solution Y-YH_0.245, yttrium dihydride - YH_1.9-YH_2.0; yttrium trihydride - YH_2.8-YH_3.0 [62Lun, 62Peb, 65Yan, 82Bon...